GDG - WHID 65040-032

GDG - WHID 65040-032 is a Video Display Controller manufactured by Sharp Corporation and used in Sharp MZ-800 and MZ-1500 computers.

Features

  • 3 graphics modes :
    • MZ-700 mode(text mode used with semi-custom CTRC)
    • MZ-800 mode 1 (using 320 x 200 resolution)
    • MZ-800 mode 2 (using 640 x 200 resolution)
  • Uses planar so that the bitplanes are in VRAM
    • MZ-800 and 1500 haves 16kb vram but you can upgrade it to 32kb
    • 4 bitplanes
  • Capable to 2-16 colors(depends from available VRAM)

Technical information

In GDG - WHID 65040-032 you can change the frequency of the screen from the Port $CF07. GDG - WHID 65040-032 also haves scrolling registers they are controlled by a scrolling control chip. Because the bitplanes are stored into vram the bitplanes take a lot of space from the vram so that with 16kb of vram its possible to use only 2-4 colors and with 32kb vram 2-16 colors(depends what graphics mode you are using).

Operating data

Sharps Service Manual for Sharp MZ-800

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